Gas lens housing for arc-welding or flame cutters with non-melting electrodes

ABSTRACT

The invention concerns a gas lens housing (20) for arc-welding or flame cutters with a non-melting electrode (4), in particular for T.I.G. welding. According to the invention, a torch member (1) comprises a housing (2) for accommodating an electrode holder (3) which optionally comprises in a front, downstream section (26) collets (28) with expansion slots (8) for clamping the electrode (4) in place. An annular duct (24) used as a protective gas duct is formed between the electrode holder (3) and a housing casing (22) and a gas lens (6) is disposed in the annular duct (24) or torch nozzle (5). The gas lens housing (20) is mounted with play at a front end (30) of the electrode holder (3).

DESCRIPTION

The invention pertains to a gas lens housing for arc welding or cuttingtorches, to be specific WIG-Torches, with a torch body with a housingfor securing an electrode holder, which can have collet chucks withexpansion slit as clamping fixture for the electrode in a frontaldownstream section, where a ring channel is created as a protectionchannel between the electrode holder and a housing jacket of the housingand with a gas lens attached to this ring channel.

Gas lens housings or gas lenses of that variety are designed at the exitof the protection channel of an arc welding or cutting torch, so thatthe inert gas can exit the torch in a laminar flow, surround or coverthe electrode and in this condition reach the welding site without beingmixed with the atmospheric air. The gas lenses could be e.g. of sinteredmetal plates, as those described in DE-GM 84 05 922, or it can also beof pressed steel wool or metal wire mesh sieve.

In torches of the initially mentioned type, the gas lenses are fastenedwithin a gas lens housing, in which for instance the sintered metalplates or the fine wire mesh sieves are secured on the guide pipe with aretainer ring, as is described in DE-AS 1 295 328. It is also possibleto fasten the sintered metal plate to the guide pipe by heading theouter end. Such an arrangement is described for instance in DE 37 28 185A1.

Furthermore, it is already common to screw or solder the gas lenshousing to the adapter sleeve housing of the torch.

Generally, the gas lens contains a center bore, which is pushed over thefront end of the adapter sleeve housing or the collet chuck of theelectrode holder. A disadvantage in this familiar arrangement is, forinstance, that, when spray or beads of weld form at the front end of theelectrode and the gas jet has to be changed, the gas lens or sections ofit tend to stick to those sprays or beads on the electrode, and there isdanger of damaging the gas lens or the gas jet.

Contrary to this, the invention has the objective to further the designof the initially mentioned gas lens housing with attached collet chuckin such a manner, that a trouble free exchange of the gas jet ispossible and, according to a side aspect of the invention, an optimalatmosphere for the inert gas is created in the area of the electrode.

The objective of the invention is further met by the fact, that the gaslens housing is affixed with play at the front end of the electrodeholder.

Because of this measure it is possible to securely fasten thecontracting collet chuck of the electrode holder in radial direction,while still fastening the gas lens housing securely to the electrodeholder. If during the welding, sprays or beads of weld have gathered onthe front end of the electrode, just a torch cap of the torch body hasto be loosened, which also loosens the clamping holder of the electrodeby the collet chuck, so that the electrode can be removed from theelectrode holder without problem. Because the electrode can be simplyremoved from the frontal downstream section of the electrode holder whenthe collet chuck is loosened, the danger of damaging the gas lens issafely avoided. Moreover, according to the invention, the fastening ofthe gas lens housing to the front end of the electrode holder does notdiminish the function of the collet chuck to fasten the electrode.

An advantageous development of the invention determines that the gaslens housing can turn around the longitudinal axis of the electrodeholder and is possibly held to the electrode holder with low axial play.This ensures an exact alignment and fastening of the collet chuck, whichespecially tends to move in radial direction when clamping tight theelectrode, even though these collet chucks assume additionally thefunction of fastening the gas lens housing.

A further advantageous further development of the invention determinesfor the electrode holder or the collet chuck to have protuberances likea kind of ring flange directed radially to the outside, while theelectrode holder is stuck through a central bore in the bottom of a potshaped outer part of the gas lens housing, so that the outer part isable to be turned in a kind of hasp on the front end of the electrodeholder. Thus the protuberances, that are radially extending to theoutside on the front end of the electrode holder, act as holding arm forfastening the outer part of the gas lens housing.

For holding the gas lens housing to the electrode holder, it is intendedfor the pot shaped receptacle of the outer part to contain a holdingelement, through which inert gas can pass and which is firmly connectedto the outer part, e.g. though a locking, deformation, interferencefitting or the like, where the protuberances that are facing to theoutside are established with play between the bottom of the outer partand the holding element. Because of the advantageous design, the gaslens housing or at least an outer part of the gas lens housing is fixedsecurely and with play to the electrode holder.

Also, the radially to the outside directed protuberances are to have aradial length, which surpasses the maximum lift of the collet chuck ofthe electrode holder for fastening the electrode in the housing. Asecure hold with play of the gas lens housing on the electrode holderis, therefore, even then safeguarded, when the collet chucks of theelectrode holder are moved radially to the inside in the direction of amiddle longitudinal axis of the electrode holder

An advantageous model of the invention has designed as fasting element apunched disk with several holes through which the inert gas can flow andwhich has a aperture in the center for the electrode to pass through.

Still, according to another advantageous and independent model of theinvention, the possibility exists for designing the holding element asan impeller wheel, a rotor or the like, so that the holding element andthe outer part together under the influence of the permeating inert gascan rotate around the longitudinal axis of the electrode holder. Becauseof this design, the inert gas is exposed to windup and is carried out ofthe gas lens, which has been shown to be advantageous for stabilizingthe arc. This measure specifically prevents the arc from wandering.

It is, of course, understood with the last mentioned model, that the gaslens housing is designed in such a way that it can rotate freely aroundthe longitudinal axis of the electrode holder, even when the electrodeis fastened in the electrode holder.

In an advantageous model of the invention, the holding element isfastened on the interior side wall of the outer part with an initialring step, ring nut or the like.

In order to achieve a further equalization of the inert gas volumeflowing from the gas lens, there is a second ring step, ring nut or thelike, in downstream direction of the first ring step, in which one orseveral sieves are able to be locked or fastened.

Beyond that, it has been proven advantageous for the sieve(s) to be ableto be locked or fastened with a central bore in a ring nut or the likeof a jacket section of the holding element. This holds the normallyquite flexible sieve(s) securely and permanently in the gas lenshousing.

Other advantages, and application possibilities of the present inventionarise from the subsequent description of a design model with the aid ofthe drawings.

The following is shown in:

FIG. 1 a WIG-Torch with an electrode holder with a collet chuck and witha gas lens that is attached with play,

FIG. 2 the electrode holder with attached gas lens according to FIG. 1,

FIG. 3 a cutaway representation of the electrode holder of FIGS. 1 and2,

FIG. 4 a top down illustration of a holding element that is designed asa punch disk

FIG. 5 a side view of the holding element of a FIG. 4, shown in partialcross section and enlarged scale,

FIG. 6 a sieve of the gas lens.

The arc welding or cutting torch of FIG. 1 is designed as air cooledWIG-Torch and contains a torch body 1 with a housing 2 for holding anelectrode holder 3. And an electrode 4 is clamped into this electrodeholder 3. The front end of the torch body 1 contains a torch jet 5, andfor better distribution of the inter gas flowing out of the torch jet 5,a gas lens 6 is provided for within the torch jet 5. This gas lens 6,which is fastened in a gas lens housing 20, assist in ensuring thelaminar flow of the inert gas stream and improved covering of thewelding spot. The inert gas is guided to the gas lens 6 via a ringchannel 24, which is formed between a housing jacket 22 of the housing 2and the electrode holder 3. The gas lens 6 and/or the gas lens housing20 are arranged in the ring channel 24 or in the torch jet 5.

The housing 2 of the torch body 1 contains a cone shaped seat 7 for theelectrode holder 3. During assembly, the torch cap 9 is screwed on theback end of the electrode holder 3, which pulls the electrode holder 3into the cone shaped seat 7. At the same time, the collet chuck 28 orthe expansion slits 8 of the electrode holder 3 are drawn together,preferably to the inside, while the electrode 4 is clamped tightlyinside the electrode holder 3.

In this design model, the collet chuck 28 with the expansion slits 8 isarranged in a frontal downstream section 26 of the electrode holder 3.At the same time, the gas lens housing 20 is held with play to a frontend 30 of the electrode holder 3. Thus it is possible to achieve anexact alignment and fastening of the collet chuck <26 or the electrodeholder> 3 which when being tightened moves to the inside.

Furthermore, the gas lens housing 20 is able to rotate and is held, onlywith little axial play, on the electrode holder 3 around a longitudinalaxis of the electrode holder 3. Moreover, the gas lens housing 20contains a ring or pot shaped outer part 10, which has a central bore 36in the bottom 38. The electrode holder 3 is pushed through this centralbore 36, while on the electrode holder 3 or the collet chuck 28, thereare protuberances 34 that are facing to the outside and are shaped likea ring flange, which overlap the bottom 38. In all, the outer part 10 isdesigned to be turned like a screw cap on the front end 30 of theelectrode holder 3.

A holding element 42, through which the inert gas flows and which isfirmly connected to the outer part 10, for instance with locking,deformation, interference fitting or the like, is inserted into thereceptacle 40 of the outer part 10, which is open to the torch jet 5.The protuberances 34 of the electrode holder 3 that are facing to theoutside are gripped between the bottom 38 of the outer part 10 and theholding element 42.

The holding element 42, especially that in FIG. 4 of the design model,is shaped like a punched disk 11 and this punch disk 11 contains severalholes 44 through which the inert gas flows, as well as a centralaperture 46 through which the electrode 4 is inserted. The holdingelement 42 of the punched disk 11 can be fastened to the outer part 10with a first ring step 12, ring nut or the like, in a interior side wall48 of the outer part 10.

It is understood, that the radial length of the protuberances 34 thatextend to the outside surpasses the maximum lift of the collet chuck 28of the electrode holder 3 when clamping the electrode 4 into the housing2. This ensures, that the gas lens housing 20 is securely fastened tothe electrode holder 3, even when the collet chucks 28 are rotated tothe inside along middle longitudinal axis 32 of the electrode holder 3.

In another model the holding element 42 can be designed as an impellerwheel, a rotor or the like, and together with the outer part 10 underthe influence of the permeating inert gas can be made to rotate aroundthe longitudinal axis 32 of the electrode holder 3. A real benefit is,that the gas lens housing 20 is designed to freely rotate around thelongitudinal axis 32 of the electrode holder 3 even when the electrode 4is fastened in the electrode holder 3 within the housing 2 of the torchbody 1.

During the assembly of the gas lens housing 20, after the holdingelement 42 has been set upon the first ring step 12 and fastened on thegas lens housing by interference fitting or deformation, one or moresieves 13 are locked or fastened with a central bore 50 to a ring nut 14on an jacket section 15 of the holding element 42 or else on the puncheddisk 11. At this time, the outer edge of the sieve 13 is locked into asecond ring step 16 or into a ring nut in the interior side wall 48 ofthe outer part 10.

These sieves 13 serve to equalize the volume of the inert gas streamacross the whole area of the gas lens. Furthermore, the holding tank 18,which is formed between the holding element 42 or the punched disk 11and the sieves 13, also ensures that the inert gas flowing through thepunched disk 11 converges evenly and homogeneously upon the sieve 13 ofthe gas lens 6.

It remains to be noted, that the punched disk 11 can be designed in onepiece construction with the jacket section 15 as a swivel part. The sameis true for the outer part 10, so all in all, the resulting assembly ofthe gas lens housing 20 is of very simple construction.

The described design model also contains longitudinal channels 17, whichare arranged over the circumference of the electrode holder 3, forconduction the inert gas to the gas lens 3. There is also theopportunity to design corresponding openings in the area of the bottom38 of the outer part 10 for passage of the inert gas to the gas lenshousing.

LIST OF REFERENCE NUMBERS

1--Torch body

2--Housing

3--Electric holder

4--Electrode

5--Torch jet

6--Gas lens

7--Seat

8--Expansion

9--Torch cap

10--Outer part

11--Punched disk

12--First ring step

13--Sieve

14--Ring nut

15--Jacket section

16--Second ring step

17--Longitudinal channel

18--Holding tank

20--Gas lens housing

22--Housing jacket

24--Ring channel

26--Front section

28--Collet chuck

30--Front end

32--Longitudinal axis

34--Fitting

36--Bore

38--Bottom

40--Receptable

42--Holding element

44--Hole

46--Aperature

48--Interior side wall

50--Bore

I claim:
 1. A gas lens housing (2) for arc welding or cutting torcheswith a non-consumable electrode (4), a torch body (1) with a housing (2)for receiving an electrode holder (3), the electrode holder (3) beingprovided with collet chucks (28) and expansion slits (8) in a front,down stream section (26) to fasten the electrode (4) in a clampingattachment, where a ring channel (24) as protective channel for an inertgas is formed between the electrode holder (3) and a housing jacket (22)of the housing and where a gas lens (6) is fitted into the ring channel(24) or the torch jet (5) characterized by the fact that the gas lenshousing (2) is mounted at the front end (30) of the electrode holder (3)or the collet chucks (28) and held with axial play.
 2. Gas lens housingaccording to claim 1, characterized by the fact that the electrodeholder (3) or the collet chuck (28) exhibits protuberances (34) that aredirected radially to the outside on its front end and that the electrodeholder (3) is pushed through a central bore (36) in the bottom (38) of apot shaped outer part (10) of the gas lens housing (20), so that theouter part (10) can be turned on the front end (30) of the electrodeholder (3).
 3. Gas lens housing according to claim 2, characterized bythe fact that a holding element (42), through which the inert gas freelyflows, is inserted into the pot shaped receptacle (40) of the outer part(10) and which is firmly connected to the outer part (10) with locking,deformation, interference fitting, while the protuberances (34) that aredirected to the outside are clasped between the bottom (38) of the outerpart (10) and the holding element (42).
 4. Gas lens housing according toclaim 3, characterized by the fact that the holding element (42) islocked in the interior side wall (48) of the outer part (10) by a firstring step (12) ring nut or the like.
 5. Gas lens housing according toclaim 3, characterized by the fact that there is a second ring step(16), in downstream direction of the first ring step (12), in which oneor several sieves (13) are able to be locked or fastened.
 6. Gas lenshousing according to claim 5, characterized by the fact that the sieveor sieves (13) can be locked or fastened with a central bore (50) in aring nut (14) of a jacket section (15) of the holding element (42). 7.Gas lens housing according to claim 2, characterized by the fact thatthe radial length of protuberances (34) that are directed to the outsideis such as to surpass the maximum lift of the collet chuck (28) of theelectrode holder (3) for fastening the electrode (4) in the housing (2).8. Gas lens housing according to claim 2, characterized by the fact thatthe holding element (42) includes several holes (44) through which inertgas can flow, with a central aperture (46) as passage for the electrode(4).
 9. Gas lens housing according to claim 2, characterized by the factthat the holding element (42) together with the outer part (10) rotatesaround the longitudinal axis (32) of the electrode holder (3) whenaffected by the permeating inert gas.
 10. Gas lens housing according toclaim 1, characterized by the fact that the gas lens housing (20) freelyrotates around the longitudinal axis (32) of the electrode holder (3)when the electrode (4) is fastened in the electrode holder (3) withinthe housing (2) of the torch body (1).